Cartridge for injecting a semi-pasty product

ABSTRACT

The injection cartridge comprises two containers (1, 2) one of which is slidably mounted in the other. An actuating rod (8) has a smooth leading portion (9) and a rear threaded portion (10) separated by a threaded intermediate portion (11). The container (1) has in its end (12) a threaded opening (13) receiving the threaded intermediate portion (11). The nozzle (5) of the container (2) has a thread (15) for receiving the thread (14). The threaded portion (10) of the rod (8) has a nut for abutting against the first container to push it towards the other container. The cartridge may be used for injecting a semi-pasty product into a protective sleeve for a joint in a telephone cable.

The present invention concerns a cartridge for injecting into a hollowbody a semi-pasty product, such as a polyurethane foam obtained bymixing two constituents, namely a polyalcohol and an isocyanate.

By semi-pasty product is meant a product the viscosity of which isbetween 500 and 2,000 centipoise.

The cartridge proposed by the invention is intended, in particular, forinjecting polyurethane foam into a sealing and electrically insulatingsleeve surrounding the splice which joins electric or electronic cables.

There is known a cartridge for injecting a semi-pasty product obtainedby mixing two constituents, comprising two containers, one containerbeing slidably mounted in the other and each container containing one ofthe aforementioned constituents. One of the containers is separated fromthe other container by a partition wall.

The other container has a discharge nozzle for connection to theinjection orifice of the hollow body. The partition wall of the firstcontainer and the discharge nozzle of the second container each have aclosure pierceable by a perforating rod mounted axially in thecartridge.

The perforation of these closures enables respectively the passage ofthe first constituent into the second container and the passage of theresulting mixture through the discharge nozzle of the second container.

Experience has shown that the use of a cartridge of this type presenteddifficulties in the case of products having a viscosity greater than orequal to 1000 centipoise.

In fact, the injection of such products involves the exertion ofconsiderable efforts to make the first container slide into the secondcontainer. It is therefore necessary to limit the dimensions of thecartridges and this requires the use of several cartridges to fillsleeves of large volume.

An object of the present invention is to eliminate these disadvantagesby providing a cartridge which is easy to handle and capable ofcontaining a volume of semi-pasty product considerably greater than thatcontained by conventional cartridges.

The injection cartridge proposed by the invention comprises twocontainers, one of which is slidably mounted in the other and each ofwhich contains one of the two constituents of the mixture to be made up,one of the containers being separated from the other container by apartition wall, this other container having a discharge nozzle forconnection to the injection orifice of the hollow body, the partitionwall and the discharge nozzle each having a closure pierceable by aperforating rod mounted axially in the cartridge, to enable respectivelythe passage of the constituent from the first container into the secondcontainer and the passage of the resulting mixture through the dischargenozzle of the second container.

According to the invention, the cartridge is characterised in that therod has a smooth leading portion and a threaded rear portion, theleading and rear portions being separated by a short threadedintermediate portion of larger diameter than the diameters of saidleading and rear portions, that the first container has, in its endopposite to the second container, a threaded opening for receiving saidthreaded intermediate portion, that the free end of the smooth portionof the rod is threaded, that the discharge nozzle of the secondcontainer has an internal thread for receiving the thread provided onthe end of this smooth portion, that the length of this smooth portionis greater than the distance between the partition wall and the threadof the first container, and that the threaded portion of the rod has anut for abutting against the outside of the cartridge on the end of thefirst container, to push this latter into the second container.

The operation of the cartridge according to the invention as follows:The rod is inserted axially into the threaded opening of the firstcontainer. The threaded intermediate portion of the rod is screwed intothis opening. During this operation, the end of the rod pierces theclosure provided in the partition wall of this container. The firstcontainer thus communicates with the second container. The constituentscontained in this container are mixed by making the first containerslide several times, relative to the second container, in bothdirections.

The rod is then pushed further into the cartridge in order to screw thethreaded end of the rod into the thread cut in the discharge nozzle ofthe second container. In this position, the threaded portion of the rodprojects outside the threaded opening of the first container. The nut isscrewed onto this threaded portion until it abuts on the adjacent end ofthe first container. Screwing of this nut is then continued, whichcauses the first container to be made to slide into the second containerwhich, in turn, causes the product resulting from the mixture of the twoconstituents to be ejected through the discharge nozzle of the secondcontainer.

Use of the cartridge according to the invention is thereforeparticularly easy and does not require any special effort. A cartridgeof this kind may be of large dimensions and this enables a hollow bodyof large volume to be filled in a single operation.

Other features and advantages of the invention will become apparent inthe following description of embodiments of the invention, given by wayof example with reference to the accompanying drawings:

FIG. 1 is a plan view of a first embodiment of the cartridge accordingto the invention;

FIG. 2 is a plan view of the perforating rod of this cartridge;

FIG. 3 is a view of the nut for effecting the sliding of one of thecontainers into the other container of the cartridge;

FIG. 4 is a view of the cartridge in a part cut-away plan view, showinga preliminary phase of use of the cartridge;

FIG. 5 is a view similar to FIG. 4, showing the next phase of use of thecartridge;

FIGS. 6 and 7 are plan views of the cartridge, the first container beingrespectively in a pressed-in position and a withdrawn position;

FIG. 8 is a part cut-away plan view of the cartridge, the end of the rodbeing in position, fixed in the discharge nozzle of the secondcontainer;

FIG. 9 is a view of the end of the cartridge, showing it beingpositioned on the injection orifice of a protective sleeve for telephonecables;

FIG. 10 is a plan view of the cartridge, showing the phase in which theproduct is injected into the sleeve, the operating nut being screwedonto the threaded portion of the rod;

FIG. 11 is a partial view of another embodiment of the rod;

FIG. 12 is a sectional view on the line XII--XII of FIG. 11;

FIG. 13 is a sectional view on the line XIII--XIII of FIG. 11;

FIG. 14 is a plan view of an operating lever for the rod according toFIG. 11;

FIG. 15 is a part cut-away plan view of another embodiment of thecartridge according to the invention, showing the end of the rodpiercing the partition wall of the first container;

FIG. 16 is a view similar to FIG. 15, showing the end of the rod screwedinto the piston;

FIG. 17 is a view similar to FIG. 15, showing the piston near thedischarge nozzle of the second container and the end of the rod screwedinto this nozzle;

FIG. 18 is an elevation view of the piston on an enlarged scale;

FIG. 19 is a sectional view on the axis of the piston;

FIG. 20 is an exploded elevation of the piston, showing its twocomponent parts;

FIG. 21 is a plan view, showing the inside of the piston;

FIG. 22 is a plan view, showing the inside of the outer member of thepiston;

FIGS. 23 and 24 are diagrams illustrating the functioning of the secondembodiment of the cartridge according to the invention.

In the first embodiment shown in the accompanying drawings, thecartridge for injecting into a hollow body a semi-pasty product such aspolyurethane foam obtained by mixing a polyalcohol with an isocyanate,consists of two cylindrical containers 1, 2, of hard plastics material,one container being slidably mounted in the other and each containercontaining one of the aforementioned constituents.

The end of the container 1 engaged in the container 2 is closed off by asubstantially frusto-conical partition wall 3 (see FIGS. 4, 5 and 8).This end of the container 1 has a toroidal seal 4 which ensuresleak-proof sealing between the two containers 1, 2.

At its opposite end from the container 1, the container 2 has adischarge nozzle 5 (see FIGS. 1 and 6 to 10), for connection to theinjection orifice 6 of a protective sleeve 7 for a telephone cable (seeFIGS. 9 and 10).

The cartridge also has a rod 8 (see in particular FIGS. 2 & 8), whichhas a leading smooth cylindrical portion 9 and a threaded rear portion10. These portions 9 and 10 are separated by a short threadedintermediate portion 11, of larger diameter than that of the leadingportion 9 or the rear portion 10.

The container 1 has a threaded axial opening 13 in its end 12 oppositeto the container 2, for receiving the threaded intermediate portion 11of the rod 8, as indicated in FIG. 5

The free end of the smooth portion 9 of the rod 8 has a screw-thread 14.

The discharge nozzle 5 of the container 2 has an internal screw-thread15 (see FIG. 8) for receiving the screw thread 14 provided on the end ofthe rod 8.

The length of the smooth portion 9 of the rod 8 is slightly greater thanthe distance between the partition wall 3 of the container 1, and thethread 13 provided at the end 12 of this container 1 (see FIG. 5). Thisthread 13 has a closure 16 of plastics material for perforation orbreaking-open, as indicated in FIG. 4. In addition, the partition wall 3of the container 1 has a pierceable closure 17 (see FIG. 5). The thread15 provided in the interior of the discharge nozzle 5 of the container 2also has a perforatable closure which is not shown in the drawings.

The threaded portion 10 of the rod 8 has a nut 18 (see FIG. 10) providedwith a lateral operating lever 19. In the position shown in FIG. 10,this nut 18 abuts against the end 12 of the container 1.

In FIG. 8, the opening 20 defined after perforation of the closure 17provided in the partition wall 3 of the container 1, is seen tocorrespond to the section of the smooth portion 9 of the rod 8.Leak-proof sealing between this smooth portion 9 and the opening 20 isthus achieved.

In addition, the threaded end 14 of the rod 8 has a bore 21, (see FIGS.2, 5 and 8) which opens laterally onto the smooth portion 9 through anorifice 22, the orifice permitting the passage of the product to beinjected.

However, it is seen from FIGS. 3, 4 and 10 in particular, that the nut18 with the lever 19 has an external thread 23 for screwing into theinternal thread 13 provided at the end 12 of the container 1 in order topierce the closure 16 located in this thread, as indicated in FIG. 4.

The operation of the cartridge just described will now be explained.

It will be assumed that the container 1 of the cartridge is filled withan isocyanate and that the container 2 contains a polyalcohol, these twoconstituents being intended to react together to form a polyurethanefoam.

A preliminary operation consists of screwing the external thread 23 ofthe nut with the lever 19 into the internal thread 13 provided at theend 12 of the container 1. This operation causes the closure 16 (seeFIG. 4) to be broken open.

The smooth portion 9 of the rod 8 is then inserted through the threadedopening 13 and the threaded intermediate portion 11 of this rod 8 isscrewed into this threaded opening (see FIG. 5).

The threaded end 14 touches the closure 17 provided in the partitionwall 3, and then breaks it open. The isocyanate then flows out into thelower container 2, by passing through the bore 21 provided in the end 14of the rod 8.

The mixing of the isocyanate with the polyalcohol is speeded up bypressing the container 1 into the container 2, as indicated in FIG. 6,and then withdrawing it again, as indicated in FIG. 7. These two motionsare carried out several times in order to achieve a homogeneous mixturebetween the two constituents. The two constituents react together toform a polyurethane foam, and this results in a considerable increase inpressure inside the container 2.

The rod 8 is then pressed into the container 2 and its threaded end 14is screwed into the thread 15 provided in the nozzle 5 (see FIG. 8). Therod 8 is thus securely fixed in the nozzle 5. The nozzle 5 is thenscrewed (see FIG. 9) into the injection orifice 6 provided on the sleeve7, and this causes the closure 24 provided in this orifice 6 to bebroken open.

The nut 18 with the lever 19 is screwed (see FIG. 10) onto theprojecting end of the threaded portion 10 of the rod 8 until this nut 18abuts against the end 12 of the container 1. By continuing to screw thenut 18 by rotation of its lever 19, the container 1 is pressed into thecontainer 2 and the opening 20 provided in the partition wall 3 of thecontainer 1 slides in a sealing manner on the smooth portion 9 of therod 8. The polyurethane foam is thus ejected gradually and withouteffort on the part of the user, through the bore 21 provided in thethreaded end 14 of the rod 8.

Very viscous (viscosity greater than or equal to 1,000 centipoise)products can thus be ejected from the cartridge and in large quantity. Alarge-volume sleeve 7 can therefore be filled in a single operation, inconditions which are particularly convenient for the user.

In the embodiment of FIGS. 15 to 17, the cartridge comprises twocylindrical containers 100 and 101, one slidably mounted in the otherand each containing a constituent of the mixture to be made up andinjected.

In the position shown in FIG. 15, a rod 102 is engaged axially in thefirst container 100. The threaded end 103 of this rod abuts against thepartition wall 104 of the first container 100 and perforates the closure105 of this partition wall, thus providing an orifice 106 in thislatter.

The cartridge has a piston 107 mounted in a sliding manner in the secondcontainer 101. This piston 107 is substantially frusto-conical. Itsouter frusto-conical surface is complementary to the interna1frusto-conical surface 101a of the end of the container 101 adjacent toits threaded nozzle 111 (see FIG. 17).

In the position shown in FIG. 15, the base 107a of the piston 107 isreceived around the partition wall 104 and it has a flange 108 intowhich a ring 109 is inserted (see FIG. 19) in order to scrape thematerial along the inside wall of the container 101.

At its opposite end from the base 107a, the piston 107 has a threadedaxial opening 110 able to receive the threaded end 103 of the rod 102,as indicated in FIG. 16.

This threaded end 103 of the rod 102 is of greater length than thethreaded portion of the opening 110 of the piston 107, so that it canproject outside this opening and can be screwed into the internal thread111a of the discharge nozzle 111 of the second container 101 (see FIG.17).

It is seen from FIGS. 19 and 20 in particular that the piston 107 hastwo frusto-conical members 112a, 112b, axially assembled one inside theother in such a manner as to leave a space 113 between them. Each member112a, 112b has two sets of openings 114, 115; 116, 117.

The largest openings 115, 117 are located near the base 107a of thepiston and the smallest openings 114, 116 are located at the oppositeend from this base.

In the embodiment shown, each set consists of three openings,distributed regularly over circles centered on the axis of the piston107.

The openings 114 of the outer member 112a are displaced angularly withrespect to the openings 115. Similarily, the openings 116 of the innermember 112b are displaced angularly relative to the openings 117.

In addition, the openings 114, 115 of the outer member 112a aredisplaced angularly with respect to the openings 116, 117 of the innermember 112b.

The space 113 between the piston members 112a, 112b, is defined bycurvilinear ribs 118 which extend over the internal face of the outermember 112a, between the central threaded orifice 110 and the flange 108(see FIGS. 21 and 22). These curvilinear ribs 118 define, between theopenings 114 of the outer member 112a and the openings 117 of the innermember 112b, on the one hand, and between the openings 116 of the innermember 112b and the openings 115 of the outer member 112a, on the otherhand, passages extending along curvilinear paths, the section of whichincreases between the free end of the piston 107 and its base 107a.

It is also seen from FIG. 22 that the interior surface of the outermember 112a has protrusions 119 between the ribs 118.

The operation of the cartridge just described is as follows:

The rod 102 is inserted into the first container 100 and the closure 105of the partition wall 104 is pierced (see FIG. 15). Communication isthus established between the two containers 100 and 101 through theinternal bore 102a of the end 103 of the rod.

Pressing-in of the rod 102 is continued and its threaded end 103 isscrewed into the threaded opening 110 provided in the end of the piston107 (see FIG. 16).

The piston 107 is then displaced towards the end of the second container101 and is then withdrawn again against the partition wall 104. This isrepeated several times in succession.

When the piston 107 is displaced towards the end of the second container101, the constituent A (see FIG. 23) contained in the container 101enters into the piston 107 through the openings 114, passes into thecurvilinear passages between the ribs 118 and emerges from thesepassages through the openings 117 (see arrow A₁ in FIG. 23). Theconstituent A is thus taken in near the axis of the container 101 and isthen mixed with the constituent B in a region located at the periphery.

During this operation, the constituent A also enters into the piston 107through the openings 115 and emerges from it through the openings 116(see arrow A₂ in FIG. 23). The constituent A is thus likewise taken inat the periphery and then mixed with the constituent B in a regionlocated near the axis.

When the piston is displaced rearwardly (see FIG. 24)--i.e. towards thefirst container 100, the constituent B contained in this enters into thepiston 107 through the openings 117 and 116 and emerges from it throughthe openings 114 and 115 (see arrows B₁ and B₂).

The constituent B is thus taken in near the axis and near the peripheryof the container 101 and mixed with the constituent A in the regionslocated near the periphery and near the axis of the containerrespectively.

The protrusions 119 located in the passages between the aforementionedopenings enable the flow of the material to be divided and this enablesthe homogenity of the mixture of the constituents A and B to beimproved.

When the mixing of the constituents A and B has finished the threadedend 103 of the rod 102 is screwed into the thread of the nozzle 111,which causes the piston 107 to be applied against the internalfrustoconical surface 101a of the end of the container 101.

The procedure as described above is then followed to inject the mixtureobtained into a hollow body, such as a protective sleeve for telephonecables.

Obviously the present invention is not restricted to the embodiment justdescribed and numerous modifications may be made to it without departingfrom the scope of the invention.

Thus, additional complementary sealing may be provided for the opening20 of the partition wall 3 of the container 1.

The end 14 of the rod 8 may be arranged in such a way as to facilitatethe piercing of different closures.

The cartridge according to the invention may also be used to injectsemi-pasty products other than polyurethane foam and obtained by mixingat least two liquid and/or solid constituents.

In the embodiment of FIGS. 11 to 13, the rear threaded portion 10a ofthe rod 8a has a star-shaped section with four points (see FIG. 12). Thesmooth leading portion 9a is identical with the region 9 of the rod 8shown in FIG. 2. The threaded intermediate portion 11a also has astar-shaped section (see FIG. 13).

The lever 19a shown in FIG. 14 and carrying the nut 18a for screwingonto the threaded portion 10a of the rod 8a has an opening 23, thestar-shaped section of which is adapted to the section of the threadedportion 10a of the rod 8a.

After introducing the rod 8a into the cartridge, the opening 23 of thelever is engaged on the threaded region 10a of the rod 8a. This levergreatly facilitates the rotation of the rod 8a when the closure 17 isbeing pierced.

Thus, the discharge nozzle 111 of the cartridge has an external threadenabling the cartridge to be screwed on to a fixed support, which wouldfacilitate the handling of the cartridge during the operation of mixingthe constituents A and B and would enable the semi-pasty product to beinjected into a hollow body from a distance.

We claim:
 1. A cartridge for injecting into a hollow body (7) asemi-pasty product obtained by mixing two constituents, comprising twocontainers (1, 2), one of which is slidably mounted in the other andeach of which contains one of said two constituents, one of thecontainers being separated from the other container by a partition wall(3), the other container having a discharge nozzle (5) for connection tothe injection orifice (6) of the hollow body, this partition wall (3)and the discharge nozzle (5) each having a closure (17) pierceable by aperforating rod (8) mounted axially in the cartridge, to enablerespectively the passage of the constituent from the first containerinto the second container and the passage of the resulting mixturethrough the discharge nozzle of the second container, characterised inthat the rod (8) has a smooth leading portion (9) and a threaded rearportion (10), the leading and rear portions being separated by a shortthreaded intermediate portion (11) of larger diameter than the diametersof said leading and rear portions, that a first said container (1) hasin its end (12) opposite to a second said container (2), a threadedopening (13) for receiving said threaded intermediate portion (11), thatthe free end (14) of the smooth portion (9) of the rod is threaded, thatthe discharge nozzle (5) of the second container has an internal thread(15) for receiving the thread (14) provided on the end of the smoothportion, that the length of the smooth portion is greater than thedistance between the partition wall (3) and the thread (13) of the firstcontainer, and that the threaded rear portion (10) of the rod (8) has anut (18) for abutment against the outside of the cartridge, on the end(12) of the first container, to push this latter into the secondcontainer.
 2. A cartridge according to claim 1, characterised in thatthe opening (20) defined after perforation of the closure (17) providedin the partition wall (3) of the first container (1) corresponds to thesection of the smooth portion (9) of the rod (8).
 3. A cartridgeaccording to claim 1, characterised in that the threads (13, 15)provided in the end (12) of the first container (1) and in the dischargenozzle (5) of the second container (2) each have a closure (16)pierceable by means of the rod (8).
 4. A cartridge according to claim 1,characterised in that the threaded end (14) of the smooth portion (9) ofthe rod (8) has a bore (21) which opens laterally on the smooth portionof the rod through an orifice (22) which permits the passage of theproduct to be injected.
 5. A cartridge according to claim 3,characterised in that the nut (18) for mounting on the threaded rearportion (10) of the rod (8) has an external thread (23) for screwinginto the thread (13) provided in the end of the first container (1) topierce the closure (16) located in this thread.
 6. A cartridge accordingto claim 1, characterised in that the nut (18) has a lever (19) fordriving it in rotation.
 7. A cartridge according to claim 1,characterised in that the rear threaded portion (10a) of the rod (8a)has a star-shaped section and that the lever (19a) for the nut (18a) hasan opening (23) adapted to said section.
 8. A cartridge according toclaim 1, characterised in that it has a piston (107) slidably mounted inthe second container (101), this piston having a threaded axial opening(110) enabling the threaded end (103) of the perforating rod (102) to bereceived, after the partition wall (104) of the first container (100)has been perforated by said end, that this threaded end of the rod (102)is of greater length than the threaded part of the axial opening (110)of the piston so that said threaded end may project out of this openingand may be screwed into the internal thread (110a) of the dischargenozzle (111) of the second container (101), and that the piston has aset of openings (114, 115, 116, 117) enabling the passage of theconstituent contained in each container towards the other and viceversa, these openings being disposed in such a manner as to divert thepath of the passage of the constituents from the axis of the secondcontainer (101) towards the periphery of said container when the piston(107) is displaced in one direction, and to divert said path from theperiphery of the second container towards its axis when the piston isdisplaced in the other direction.
 9. A cartridge according to claim 8,characterised in that the piston (107) is substantially frustoconical,its base (107a) adjacent to the partition wall of the first container(100) having a flange (108) in which an annular seal (109) is engaged toestablish leak-proof sealing with the second container (101), that ithas two frustoconical members (112a, 112b), axially asembled one insidethe other in such a manner as to leave a space (113) between them, andthat each member has two sets of openings (114, 115; 116, 117), one ofthese sets being located near the base (107a) of the piston and theother set being located at the opposite end from said base, and theopenings of one of the members being displaced with respect to theopenings of the other member.
 10. A cartridge according to claim 9,characterised in that the two members (112a, 112b) of the piston (107)are separated by ribs (118) which define curvilinear paths for passageof the constituents.
 11. A cartridge according to claim 10,characterised in that said curvilinear paths extend on the one hand,between the various openings (114) provided in the outer member (112a)at the opposite end from its base (107a) and the various openings (117),displaced relative to these, provided in the inner member (112b) nearthe base of the piston, and on the other hand, between the variousopenings (115) provided in the outer member (112a) near its base and thevarious openings (116), displaced with respect to these, provided in theinner member (112b) at the opposite end from its base.
 12. A cartridgeaccording to claim 11, characterised in that the openings (115, 117)located near the base of the piston (107) are larger than those locatedat the opposite end from this base.
 13. A cartridge according to claim9, characterised in that each member (112a, 112b) has two sets of threeopenings, distributed evenly over two separate circles centered on theaxis of the piston (107).
 14. A cartridge according to claim 9,characterised in that the external frustoconical surface of the piston(107) is complementary to the internal frustoconical surface (101a) ofthe end of the second container (101) adjacent to the discharge nozzle(111).
 15. A cartridge according to claim 10, characterised in that theinternal surface of one of the piston members is provided withprotrusions (119) between the ribs (118) which define the curvilinearpaths for passage of the constituents.
 16. A cartridge according toclaim 10, characterised in that the ribs (118) and the protrusions (119)are provided on the internal surface of the outer member (112a).
 17. Acartridge according to claim 8, characterised in that the dischargenozzle (111) of the cartridge has an external thread enabling screwingof the nozzle onto a support.